Re: RTL PUA?

2011/8/22 Joó Ádám <adam_at_jooadam.hu>:
>> Um... Computers are hardware, and don't understand a thing. What I think you mean is computer _software_. (I know, I'm being pedantic, but with good reason.)
>
> Sorry, I just can’t resist pointing out that difference between
> hardware and software is only the fact that the former is material,
> with all the consequences that follows. In any other way they are
> completely interchangeable.

Same opinion for me.

> As for the other part of your mail, Peter, sorry, but it really
> doesn’t make any sense to me. As John has pointed out, you can adjust
> the properties of private use characters on Apple computers. Perhaps
> there is a way to do so on Windows, Unix and other systems as well.
> What Philippe and Doug are proposing, and I also strongly agree with,
> is to have a standard way of interchange of these properties. I don’t
> think it is neccessary to go into the advantages of standards.
>
> Speaking of actual implementation, I’m convinced that this format
> should be the same as it is for encoded characters (whether it is the
> plain text format of the Unicode Character Database, XML or anything
> else). Rendering engines should – maybe they already do so – accept
> multiple files containing character properties, which could make
> upgrades to the newer versions of the standard a matter of downloading
> the new standard set, and provide a way of overriding private use (or
> even standard if one is so inclined) characters’ properties.
> Introduction of unencoded scripts would therefore become a matter of
> distributing a small properties file and the corresponding fonts.

As well, the small properties files can be embedded, in a very compact
form, in the PUA font.

This small table can be limited to just listing the ranges of PUA code
points that are strong RTL instead of LTR. Most often, there will be
only one range, and this just requires a couple of integers in that
embedded table (possibly more, only if you want to represent more
properties), without requiring a complex XML parser or a complex
parser for the tabulated ASCII format used in the UCD, which is
overkill for just the few properties that are needed for correct
display.

So the duplication in each font is not a real problem (note that there
won't be a lot of fonts, most often there will be only one that
matches the PUA agreement and that is suitable to render the
UCS-encoded PUA text).
Received on Mon Aug 22 2011 - 10:45:50 CDT